Navigation apparatus for displaying a map by limit information

Abstract

A navigation apparatus includes a road data memory (16) for storing therein road data of position and shape data at every road, a road map making device (14) for making road map data by reading road data of a predetermined scope from the memory device (16), a route selecting device (14) for selecting a route on a road indicated by road map data for destination, and a video signal generating device (17) for generating a video signal for displaying a road map under the condition that symbols indicating the route selected by the route selecting device (14) are superimposed upon the road map data made by the road map making device (14), wherein shape data of minor roads existing at an intersecting point of roads are used as road data stored in the memory (16). The navigation apparatus can display a route at a crossing of complicated shape more accurately in conformity with the actual route.

What is claimed is: 
     
       1. A navigation apparatus for navigating a navigation object comprising: road data memory means having road data and shape data including shape data of an intersecting point of an at least one road crossing;   map making means for making a map from said road data of said road data memory means;   route guide means for making a route for the navigation object to travel from said road data of said road data memory means; and   positioning means for positioning a present position of the navigation object corresponding to said map of said map making means.   
     
     
       2. The navigation apparatus for navigating a navigation object as claimed in claim 1, wherein said shape data of at least one crossing are attached to said road data of said road data memory means. 
     
     
       3. The navigation apparatus for navigating a navigation object according to claim 1, further comprising display signal generating means for generating a display signal for displaying said map of said map making means, and wherein said route guide means makes said route based on said shape data of at least one crossing of said road data memory means. 
     
     
       4. The navigation apparatus for navigating a navigation object according to claim 3, further comprising display means for displaying said route based on said display signal. 
     
     
       5. A navigation apparatus for navigating the navigation object according to claim 4, further comprising sound making means for informing a user of a predetermined message by sound in case the present position goes into a predetermined scope of area. 
     
     
       6. The navigation apparatus for navigating a navigation object as claimed in claim 1, wherein said positioning means is a global positioning system. 
     
     
       7. The navigation apparatus for navigating a navigation object according to claim 1, further comprising receiving means for receiving information transmitted on electromagnetic waves. 
     
     
       8. A computer readable medium storing data for a computer for causing the computer to make an image of a map, comprising: road data including several road positions; and   shape data of a plurality of road crossings including shape data of intersecting points of said plurality of road crossings, wherein said shape data of said plurality of road crossings are attached to said road data.   
     
     
       9. A car comprising: a body;   wheels attached to said body; and   a navigation apparatus mounted on the car for navigating the car, said navigation apparatus including road data memory means having road data and shape data including shape data of an intersecting point of at least one road crossing, map making means for making a map from said road data of said road data memory means, route guide means for making a route for the car to travel, and positioning means for positioning a present position of the car corresponding to said map of said map making means.   
     
     
       10. A car comprising: a body;   wheels attached to said body; and   a navigation apparatus mounted to the car for navigating the car, said navigation apparatus including road data memory means having road data and shape data including shape data of an intersecting point of at least one road crossing, map making means for making a map from said road data of said road data memory means, route guide means for making a route for the car to travel based on said shape data of at least one crossing, positioning means for positioning a present position of the car corresponding to said map of said map making means, and display signal generating means for generating a display signal for displaying said map of said map making means.   
     
     
       11. A navigation method of navigating a navigation object comprising: a road data reading step for reading road data and shape data including shape data of an intersecting point of a road crossing from a road data memory;   a map making step for making a map from said road data;   a route guiding step for making a route based on said shape data of the crossing;   a positioning step for positioning a present position of said navigation object corresponding to said map; and   a display signal generating step for generating a display signal for displaying said map.   
     
     
       12. A road display signal generating apparatus for generating a signal for displaying a road comprising: road data memory means having road data and shape data including shape data of an intersecting point of at least one road crossing;   map making means for making a map from said road data of said road data memory means; and   route guide means for making a route corresponding to said map of said map making means.   
     
     
       13. A road display apparatus for displaying a road comprising: road data memory means having road data and shape data including shape data of an intersecting point of at least one road crossing;   map making means for making a map from said road data of said road data memory means;   route guide means for making a route corresponding to said map of said map making means; and   display means for displaying a map and a route made by said map making means and said route guide means, respectively.   
     
     
       14. A computer apparatus for generating a signal for displaying a road comprising: road data memory means having road data and shape data including shape data of an intersecting point of at least one road crossing;   map making means for making a map from said road data of said road data memory means; and   route guide means for making a route corresponding to said map of said map making means.